Both alcohol use and school bullying have negative short-term effects on students' physical and psychological health and long-term effects on their psychosocial adjustment. Despite a proliferation of prevention program targeting these problem behaviors, both remain prevalent. Prevention program(s) to address these problems behaviors compete for time and resources with school priorities to meet academic standards and many programs delivered in schools, unfortunately, focus only on specific negative behaviors and deficits (e.g., poor decision making skills), and label adolescents as problems in need of fixing. While these prevention programs can reduce or prevent negative behaviors, they tend not to improve key developmental outcomes, in part because they are usually delivered as a stand-alone curriculum inserted into the school day and do not address the school environment. One positive youth development (PYD) program, the Restorative Practices Intervention or RPI, shows particular promise because it is a whole school environment intervention which is integrated into existing school practice (rather than 'added on') and quasi-experimental evidence supports its effectiveness at improving the environment, reducing problem behaviors like alcohol use and bullying, and promoting positive relationships. Despite this evidence, questions remain about the exact mechanisms by which the results were achieved and whether results persist. Thus, more rigorous research is needed to assess RPI's impacts and the underlying program mechanisms that achieve positive outcomes across these areas. Identifying programs that can integrated into school practice, and that can affect both developmental outcomes and problem behaviors of middle school youth is critical as alcohol use and bullying remain high and states are cutting funding to implement typical standalone prevention programs and limiting the amount of time spent on these programs. With the current economic climate, it is imperative to find efficient and lasting alternatives. The proposed study responds t PA-08-241: Reducing Risk Behaviors by Promoting PYD by proposing the first longitudinal randomized controlled trial to document whether an integrated whole-school program like RPI can affect both developmental outcomes and problem behaviors. The proposed study would assess the mechanisms through which RPI influences the school environment; its effects on adolescents' school connectedness, peer relationships, developmental outcomes (academic achievement, social competency) and problem behaviors (alcohol use, bullying, disciplinary referrals); and the extent to which the effects persist during the transition between middle and high school.